Prac SPI bit-banging

#include <xc.h>
#include <p18f4550.h>
#define _XTAL_FREQ 8000000   // Need for __delay_ms function
#include <delays.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include "config.h"
#include "touchscreen.h"
#include "GLCD.h"

#define ADC_THRESHOLD 10
extern unsigned const char font5x7[];
extern unsigned const char font5x72[];
byte zeros[128];
byte cal_x_min,  cal_y_min, cal_x_max,  cal_y_max;
int x_coord_old, y_coord_old, x_coord64, y_coord128;

byte tpCoord (byte x, byte y);

#define DADES  PORTBbits.RB0
#define CLOCK  PORTBbits.RB6
#define LATCH  PORTBbits.RB2
#define ENABLE PORTBbits.RB4

#define BLAU  0x3FF00000
#define ROIG  0x000FFC00
#define VERD  0x000003FF
#define BLANC 0x3FFFFFFF
#define NEGRE 0x00000000

void spi_bb_init()
{
    TRISB = 0x00; //Port B output
}

void spi_bb_send32(unsigned long int b)
{
    LATCH = 0;
    CLOCK = 0;
    ENABLE = 0;
    int i;
    for (i = 0; i < 32; i++) {
        DADES = (b>>(31-i)) & 0b1;
        CLOCK = 1;
        __delay_ms(1);
        CLOCK = 0;

    }
    CLOCK = 0;
    LATCH = 1;
    ENABLE = 1;
    LATCH = 0;
}

void main()
{
    cal_x_min = 47;  cal_y_min = 14;  // Valor cal·libracio per defecte
    cal_x_max = 221; cal_y_max = 222;  // Son els necessaris per la simulacio en PROTEUS

    tpInit();
    spi_bb_init();

    while (1) {
        byte tsX = tpGetY();
        __delay_ms(1);
        byte tsY = tpGetX();

        //Pressionat
        if ((tsX > ADC_THRESHOLD) && (tsY > ADC_THRESHOLD)) {
            if (tpCoord(tsX, tsY)) {
                //Superior
                if (x_coord64 < 32) {
                    //Esquerra
                    if (y_coord128 < 64) {
                        spi_bb_send32(VERD);
                    } else { //Dreta
                        spi_bb_send32(BLAU);
                    }
                } else { //Inferior
                    //Esquerra
                    if (y_coord128 < 64) {
                        spi_bb_send32(BLANC);
                    } else { //Dreta
                        spi_bb_send32(ROIG);
                    }
                }
            }
        } else { //No pressionat
            spi_bb_send32(NEGRE);
        }
    }
}


byte tpCoord (byte x, byte y)
{
    int x_coord, y_coord, x_coord_diff, y_coord_diff;
      // After a PRESS is detected read X-Y and convert it to 64x128 space
      x_coord = (int)x - cal_x_min;
      y_coord = (int)y - cal_y_min;

      // When lifting pen from the touchpanel surface tpGetX and tpGetY readings
      // (after correct PressDetect reading) may be incorrect
      if ( x_coord > x_coord_old ) { x_coord_diff = x_coord - x_coord_old; }           // Compare with old values
      else                         { x_coord_diff = x_coord_old - x_coord; };
      if ( y_coord > y_coord_old ) { y_coord_diff = y_coord - y_coord_old; }
      else                         { y_coord_diff = y_coord_old - y_coord; };

      x_coord_old = x_coord;                               // Save old values
      y_coord_old = y_coord;

      if ( (x_coord_diff>15) || (y_coord_diff>15) ) return (0);      // If difference is too big then ignore the reading

      y_coord128 = (y_coord * 128) / (cal_y_max - cal_y_min);
      x_coord64 = (64 -(x_coord *64) / (cal_x_max - cal_x_min));

      /* if ((x_coord64 < 0) || (x_coord64 > 63))   return(0);
      if ((y_coord128 < 0) || (y_coord128 > 127))   return(0); */
      if (x_coord64 < 0)    x_coord64=0;
      if (x_coord64 > 63)   x_coord64=63;
      if (y_coord128 < 0)   y_coord128=0;
      if (y_coord128 > 127) y_coord128=127;

      return(1);
}